1. Field
The present disclosure relates to a process for the production of fatty acid methyl esters (e.g., biodiesel), and more particularly to such a process using variable feedstock and heterogeneous catalysts.
2. Description of Related Art
Typical biodiesel production processes are centered on the trans-esterification of low Free Fatty Acid (FFA) lipids. FFA levels vary from 0% in highly refined and treated oils such Soybean or Canola oils to 100% in Coconut oil. When FFA's are present they are saponified (turned into soap) by the trans-esterification reaction and represent a loss in yield unless pre-treated through acid esterification.
Traditional catalysts for acid esterification and base trans-esterification are homogeneous catalysts, which is to say they are in the same phase as the reactants (liquids in this case) and cannot be separated. When acid esterification is used, the acid is neutralized by a base, typically by the base catalyst which may then be used to carry out a base catalyzed trans-esterification reaction. However, the neutralization of the acid creates impurities in the form of salts which for biodiesel applications requires removal from the product stream. In the case where a producer does not use acid esterification to treat the FFA's in their feedstock, the resulting soap may also require removal from the product streams. In either case, time and energy are expended to remove excess catalyst, salts, or soap to obtain a product that may be used as biodiesel. It would be desirable to reduce or eliminate such requirements.